The function post_form service formgen creates a GET <form>
to service. The content of the <form> is generated by the
function formgen, that takes the names of the service
parameters as parameters. By default, the action attribute is
a relative URL recomputed at each request with make_uri.

By default, the form is realized such that the client-side Eliom
application keeps running irrespectable of the usage of the form
(cf. Eliom_client.​change_page ).

By contrast, if the optional parameter ~xhr:false is given,
the form is realized as a standard HTML form and submitting it
discontinues the Eliom application. The ~xhr parameter has no
effect outside an Eliom application.

The function post_form service formgen get_params creates a
POST <form> to service preapplied to the GET parameters
get_params. The content of the <form> is generated by the
function formgen, that takes the names of the service
parameters as parameters. By default, the action attribute is
a relative URL recomputed at each request with make_uri.

The optional parameter ~a allows one to add HTML attributes to
the generated node.